Japanese Patent Laying-Open No. 2011-78296 (PTD 1) discloses a converter including four transistors and four diodes, and configured to convert an AC voltage into a high voltage, a low voltage and an intermediate voltage. According to this converter, among four diodes, each of two diodes performing a reverse recovery operation is formed of a wide band gap semiconductor, thereby reducing recovery loss. Also, each of two diodes not performing a reverse recovery operation is formed of a semiconductor other than such a wide band gap semiconductor, thereby reducing cost.